FLUID, ELECTROLYTE, AND ACID-BASE BALANCE

1. FLUID, ELECTROLYTE, AND ACID-BASE BALANCE NUR 102 - Chapter 14

2. Body fluids • Extracellular fluids (ECF) • Interstitial fluid - fills the spaces between most cells of the body • Intravascular fluid - plasma (WBC, RBC and platelets in this fluid)

3. Body fluids • Intracellular fluids (ICF) • Liquids within cell membranes • 40% of body weight

4. Components in body fluids • Electrolyte • an element that when dissolved can carry an electrical current • Cations - (+) ; Anions - (-) • neuromuscular function • acid-base balance

5. Components of body fluids • Minerals • ingested compounds • serve as catalysts in nerve response, muscle contraction, and metabolism of nutrients in foods, regulate electrolyte balance

6. Movement of body fluids • Diffusion • Area of higher concentration to an area of lower concentration till even distribution • Osmosis • Movement of a pure solvent, e.g. water through a semipermeable membrane from a solution that has a lower solute concentration to one that has a higher solute concentration

7. Osmotic pressure • Drawing power of water (dependent on the number or molecules in solution) • Isotonic • Hypotonic • Hypertonic

8. Movement of body fluids • Filtration • Water and diffusible substances move together in response to fluid pressure • Active transport • Requires energy • Able to move larger molecules and go from less to greater concentration

9. Fluid Intake • Hypothalamus - thirst control center • Oral fluid intake requires an alert state • Osmoreceptors - monitor osmolality

10. Fluid Output • Loss through the kidneys and GI tract • Insensible • Sensible

11. Cations • Sodium (Na+) • Most abundant in the extracellular fluid • Maintains water balance, transmits nerve impulses, contracts muscles • Values - 135-145 mEq/L

12. Cation • Potassium (K+) • Major intracellular cation • Regulates neuromuscular excitability, muscular contraction, and acid-base • Value - 3.5 -5.3 mEq/L

13. Cation • Calcium (Ca2+) • Cardiac conduction, blood coagulation, bone growth and formation, & muscular relaxation • Value - 4 - 5 mEq/L

14. Cation • Magnesium (Mg2+) • Second most important of intracellular fluids • Enzyme activities, muscular excitability • Value - 1.5 - 2.5 mEq/L

15. Electrolyte Imbalances • Hyponatremia • GI losses, sweating, & diuretics • S/S: N/V/D, abd cramps, personality change • Hypernatremia • Ingestion of large amounts • S/S: Dry tongue and mucous membranes, restlessness, convulsions, thirst, dry skin

16. Electrolyte imbalances • Hypokalemia • Causes: K+ wasting diuretics • N/V/D • polyuria • S/S: weak, irregular pulse • hypotension • weakness

17. Electrolyte imbalances • Hyperkalemia • Causes: Renal failure • S/S: irregular slow pulse, weakness, irritability

18. Electrolyte Imbalances • Hypocalcemia • Causes: Vitamin D deficiency • S/S: Numb and tingling fingers and circumoral region, muscle cramps • Hypercalcemia • Causes: osteoporosis, prolonged immobilization • S/S: decreased muscle tone, weakness, lethargy, kidney stones

19. Electrolyte imbalances • Hypomagnesemia • Causes: malnutrition and alcoholism polyuria • S/S: muscular tremors, hyperactive deep tendon reflexes • Hypermagnesemia • Causes: Renal failure • S/S: hypoactive deep tendon reflexes, shallow and slow respirations

20. Acid - Base Balance • Blood pH - 7.35 - 7.45 • paCO2 - 35 - 45 • Bicarbonate (HCO3) - 22-26 mEq/L

21. Respiratory Acidosis • pH < 7.35 • paCO2 > 45 mm Hg • Causes: Respiratory failure • Hypoventilation • Resp muscles paralysis • Airway obstruction

22. Respiratory Alkalosis • pH > 7.45 • paCO2 < 35 mm Hg • Causes: excessive exhalation of CO2 (hyperventilation)

23. Metabolic Acidosis • pH < 7.35 • bicarbonate - < 22 mEq/L • Causes: Starvation, DKA, Diarrhea, drug use

24. Metabolic Alkalosis • pH > 7.45 • bicarbonate > 26 mEq/L • Causes: excessive vomiting, prolonged gastric suctioning

25. Fluid & Electrolyte Imbalances • Burns - body fluid loss • Renal D/O - abnormal retention of Na, Cl, K • GI Disturbances - Loss of fluid, potassium, and chloride • Exercise

26. S/S electrolyte imbalance • Head: irritability • Fontanels: depressed, bulging • Eyes: sunken periorbital edema • Mouth: mucous membranes • CV: neck veins, edema, blood pressure • Resp: Crackles

27. Imbalances • GI: abdomen, V/D • Renal: Oliguria or anuria (FVD, FE) • Diuresis (FVE) • Increased urine spec. gravity (FVD) • Skin (Temp) • increased - met acidosis, hypernatremia • decreased - FVD

28. Replacement of fluids and electrolytes • Types of IV fluids • Isotonic • Hypertonic • Hypotonic

29. IV complications • Infiltration • IVF enter SQ space • Phlebitis • vein inflammation • S/S: pain, redness, warmth • Fluid overload • Fluids given too rapidly • Bleeding

30. Discontinuing an IV • Stop infusion • Remove tape • 1 - 2 minute pressure

31. Blood transfusions • Large bore catheter (18 ga or larger) • Give with normal saline • Baseline vital signs • Double check with two RNs • Begin transfusion slowly • Observe closely for first 15 min

32. Transfusion Reactions • Caused by: • blood incompatibility • allergic sensitivity • S/S: fever, chills, rash, hypotension, shock • Treatment: stop transfusion, give NS, save tubing, prepare for emergency drugs